unit 3: atomic structure featuring these scientists and more!

Unit 3: Atomic Structure Featuring these scientists and more!

Castagno Chemistry Challenge III Unit 3 Day 1 Rules: 1) You are working as a CLASS and as individual groups so you can whisper amongst the table but if youre too loud youll be helping out your opponents! 2) You will have 6min 10s, the clock will be on the board! 3) Credit only goes to COMPLETELY correct answers POINTS Class:1 st 2pts, 2 nd 1pt, 3 rd 0pts, 4 th 0pts Group: 1 st 1pt bonus Questions?

Castagno Chemistry Challenge III Unit 3 Day 1 You will be presented with a wordsearch without a word bank. There are 37 terms. 6mins 10s allows you 10seconds for each word! The Challenge: Find as many as you can.

Unit 3 Objectives Definitions: atom, proton, neutron, electron, atomic theory, electron configuration, atomic number, mass number, atomic mass unit, isotope, Avogadros number. The arrangement and behavior of subatomic particles according to modern theory. The history of atomic theory from Democritus to modern quantum theory (Bohr/Schrodinger). The experiments that led to the discoveries of the subatomic particles. How to use the aufbau principle, Paulis exclusion principle, and Hunds rule to arrange electrons in atoms. That atoms can gain energy and then emit it in the form of visible light. The color (wavelength) of this light can be used for identification purposes. The energy levels and sublevels in an atom. The difference between atomic number and mass number in calculation as well as purpose. How to connect atomic mass and atomic weight. How to calculate atomic mass when given isotopes. Avogadros number is 6.02 x 10 23.

Essential Questions What is the modern description of an atom? How are atoms counted? GUIDING QUESTIONS: What does an atom look like? What are the components and features of an atom? What are the atomic theories proposed by Democritus, Dalton, and Bohr? What are the main points in the modern atomic theory? Who ran the experiments that discovered the subatomic particles? How can light be used to describe the behavior of atoms? What are the properties and locations of electrons, protons, and neutrons? How can the arrangement and location of electrons in atoms be expressed? What are the aufbau principle, Paulis exclusion principle, and Hunds rule? How is electron configuration and orbital notation written for an element? What is an energy level and what is a sublevel? How does an atomic number differ from a mass number? How and why was the atomic mass unit established? What is an isotope? What is Avogadros number?

Your Take Atoms in the world? P1 Lasers How do we see atoms? Nuclear weapons Radiation Time travel Do we touch anything? (p4) What makes things different colors? What makes light bright? Atoms in a vacuum (P6) Magnification needed to see an atom Plum pudding? Atomic theory/models How an atom was discovered? How small are atoms? How do glow sticks/glow in the dark stuff work (P7) Radioactive rocks Atoms in the body

Castagno Chemistry Challenge III Unit 3 Day 2 Rules: 1) You are working as a CLASS and as individual groups so you can whisper amongst the table but if youre too loud youll be helping out your opponents! 2) You will have 5 minutes, the clock will be on the board! 3) Credit only goes to COMPLETELY correct answers POINTS Class:1 st 2pts, 2 nd 1pt, 3 rd 0pts, 4 th 0pts Group: 1 st 1pt bonus Questions?

Castagno Chemistry Challenge III Unit 3 Day 2 You will be presented with a crossword. You will be presented with the wordsearch from the first Challenge of the unit. There are 37 terms. The Challenge: Fill out as many as possible

Preassessment 1) Match the scientist with his atomic model: Bohra) Plum pudding Aristotleb) Solar system Thomsonc) Infinitely divisible 2) What is the electron configuration of sulfur? 3) How many protons, neutrons, and electrons can be found in a Zinc-66 atom? 4) Draw what an atom looks like.

The Atom as Ancient History* The following laws Conservation of Matter Definite Proportion Multiple Proportion Were derived from observations on the behavior of matter. Interestingly these were formulated BEFORE science knew what the atom was even composed of!

Atomos the Greek God of Atoms* The Greeks were the first to discuss what stuff was made of. Democritus Leucippus Epicurus Lucretius Zeus preparing to slay the n00b god.

Democritus 460 370BC*

Democritus II* First (or generally credited as first) to theorize that matter was not infinitely divisible. He called the smallest possible part of matter atomos So, what did they look like?

Democritus II* Atoms of matter reflected general properties Iron atoms = strong and solid Water atoms = smooth and fluid So the first diagram of an atom

Where We Stand #1* The history of the atom is a long one, so at the beginning of our journey, this is what is believed 1) Democritus (~400BC) atomos The Atom

Ancient Street Brawl* Theres a good reason you havent heard of Democritus before. Aristotle 384BC 322BC He did not believe Democritus (or other atomists) theories.

Ancient Street Brawl II* His theory can be summarized as No atomsno substances even, but principles His popularity and fame ( or the fact the people didnt think for themselves ) set chemistry back 2000 years

Where We Stand #2* 1) Democritus ~400BC, atomos 2) Aristotle ~360BC, principles The Atom

From the darkness, a hero rises After 2000 years and alchemists attempting to turn urine (among other things) into gold, John Dalton comes to the rescue Dalton was colorblind so even if this engraving was in color, it would still look the same to him.

Teacher, Quaker, Weatherman, Father Finally, someone was going to stand up to Aristotle and use actual science! This is why Dalton is known as the Father of Atomic Theory.

Daltons Atomic Theory Point 1 All matter is composed of extremely small particles called atoms. Of course this wasnt Daltons idea at all, but Democritus

Daltons Atomic Theory Point 2 All atoms of a given element are identical, having the same size, mass, and chemical properties. Atoms of a specific element are different from those of any other element.

Daltons Atomic Theory Point 3 Atoms cannot be created, divided into smaller particles, or destroyed. Doesnt this sound familiar? Law of Conservation of Matter!

Daltons Atomic Theory Point 4 Different atoms combine in simple whole-number ratios to form compounds. This is an example of the Law of Multiple Proportions. It is why water is H 2 O and not H 2.5 O 1.2

Daltons Atomic Theory Point 5 In a chemical reaction, atoms are separated, combined, or rearranged. Doesnt this sound familiar? Law of Conservation of Matter!

Daltons Summary Essentially he took the ideas of the time and, noticing a trend, compiled them into a theory.

Where We Stand #3* 1) Democritus ~400BC, atomos 2) Aristotle ~360BC, principles 3) Dalton ~1808 AD, first atomic theory The Atom

Back Where We Started* Daltons work just puts as back at the beginning of the story.

Breaking Down the Atom We bravely leave the world of chemistry to journey to the world of physics. J.J. Thomson conducted the Cathode Ray Tube experiment.

Thomsons CRT Experiment http://youtu.be/XU8nMK kzbT8 http://youtu.be/XU8nMK kzbT8 Or http://www.you tube.com/watch ?v=Rb6MguN0Uj 4 http://www.you tube.com/watch ?v=Rb6MguN0Uj 4

What It All Means Thomson concluded that the green was not light but particles.

What It All Means II The particles were affected by magnets and other fields so they had a charge.

What It All Means III A simple mass-to- charge ratio calculation resulted in a particle mass SMALLER THAN HYDROGEN!

CRT Conclusion Thomson concluded that the particles, which he called corpuscles, were A) Negative B) Smaller than hydrogen

HOLD ON A MINUTE If matter is neutral, how does something exist that is purely charged? The Atom

HOLD ON ANOTHER MINUTE If the atom looks like this then how can something exist that is smaller than it? The Atom

Save Room for Dessert Daltons indivisible atom is incorrect. Matter is still neutral so Thomsons final conclusion must satisfy both facts.

Hmmmmm plum puddddddddding Thomsons atom included electrons (corpuscle is a silly name, they said) set within a positively charged pudding His atomic model is called the plum pudding model.

Where We Stand #4* 2) Aristotle ~360BC, principles 3) Dalton ~1808 AD first atomic theory 4) Thomson 1897 AD, plum pudding

Going for the Gold Thomson won a Nobel Prize for his efforts but we know that the structure of the atom is much different than his model.

Ernest (East) Rutherford The next major step in understanding the structure of the atom involved using a nuclear radiation source and gold Sounds unsafe and expensive so lets replicate it!

Geiger-Marsdennah, Rutherford The Gold Foil Experiment by any other name Video: http://youtu.be /XBqHkraf8iE http://youtu.be /XBqHkraf8iE Or http://www.yo utube.com/wat ch?v=dNp- vP17asI http://www.yo utube.com/wat ch?v=dNp- vP17asI

Gold Medal Conclusion I According to Thomsons model, the alpha particles should pass through the atom uninhibited. However, the experiment showed that some particles were deflected.

Gold Medal Conclusion II Roughly 1 in 8000 particles were deflected Rutherford concluded that A dense bundle of mass is present He called it the nucleus

Gold Medal Conclusion III* Although he was correct that the nucleus was positive, he was unaware at the time that it consisted of positive (protons) and neutral (neutrons) particles. 1911 discovery of nucleus 1920 existence of protons 1921 theorized existence of neutrons which was proved in 1935 Ironically, Rutherford (who won the Nobel Prize in Chemistry in 1908) did not win the Nobel Prize in Physics for this work but James Chadwick did for proving the existence of the neutron.

Where We Stand #5* 3) Dalton ~1808 AD first atomic theory 4) Thomson 1897 AD, plum pudding 5) Rutherford - ~1911 AD, nuclear atom The Atom

Ring Around the AtomPockets full ofAtoms. Most of your drawings of an atoms had the electrons on some sort of ring around the nucleus

Well This Sure Isnt Bohring The first real insight into the behavior of an atom came from the study of hydrogen It is the smallest atom (1 proton and 1 electron) and therefore the easiest to study

Hydrogen Emission Spectrum Niels Bohr was the first to describe the behavior of an atom mathematically Video: http://www.youtube.com /watch?v=QI50GBUJ48s http://www.youtube.com /watch?v=QI50GBUJ48s

Bohr and his Model As the video showed, this is the model he developed Electrons can exist on a ring, move from one to the other, but never inbetween.

Electrons Activate So the electrons with normal energy occupy the ground state. However, sometimes the electrons present gain energy and enter an excited state. When they then lose energy and fall back to the ground state, they give off electromagnetic radiation.

Electromagnetic Spectrum Visible light is a small portion of the entire spectrum. High energy (short wavelength) is on the left while lower energy (long wavelength) is on the right.

The First Theory that Sort of Works Bohrs model is very simple. It looks like a solar system. Nucleus at the center with electrons as planets orbiting it. Unfortunately for him, his model only works for atoms with 1 electron. Fortunately for him, his theory was the foundation for greater understanding of atoms and he won the Nobel Prize in 1922 for this work.

Where We Stand #6* 4) Thomson 1897 AD, plum pudding 5) Rutherford - ~1911 AD, nuclear atom 6) Bohr, - 1913 AD, Solar System Model The Atom

Back to the Basics Well, it is only basic if you understand Einstein and have heard of a man named Louis de Broglie.

Back to the Basics II Bohrs model explained why hydrogen emits specific colors But something was preventing his model from working with all atoms

unit 3: atomic structure featuring these scientists and more!

Documents

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